This invention relates to visual display apparatus, particularly for ground-based flight simulators and particularly for providing a display covering a wide-angle field of view. The invention provides such apparatus capable of providing three-dimensional viewing for a sole pilot.
The apparatus is of the head-coupled area-of-interest type, wherein an image is projected upon a screen and is appropriately changed both according to the simulated craft position and heading and according to the viewer's instantaneous line of view and is simultaneously moved on the screen to occupy the viewer's field of view.
Apparatus of this type is known. Such apparatus provided an area-of-interest display for a sole viewer which was pseudo-collimated, that is, the same image was projected for left and right eyes, so as to appear at infinity.
The present invention extends the capability of such apparatus to provide a three-dimensional display.
Accordingly, the invention provides head-coupled, area-of-interest, visual display apparatus providing three-dimensional viewing for one viewer, comprising a part-spherical retro-reflective screen of area greater than a viewer's instantaneous field of view, a helmet, sensing means for sensing the orientation of the viewer's head and helmet, visual image generating means for generating an image representing a simulated view in the direction of the viewer's instantaneous line of view according to the viewer's simulated position and heading and under control of the said sensing means, the said image generator being adapted for providing two visual images corresponding respectively to the viewer's left eye and right eye views, a laser light source, separate laser beam modulators for the left eye and right eye views, separate line scanners for each said view for scanning the modulated laser beam over the input ends of respective fibre optic light guides, the said fibre optic light guides having their output ends at spaced-apart positions on the viewer's helmet, and frame scanning means mounted on the said helmet for receiving light from the light guide outputs and projecting the light as a scanned image upon the said screen.
Preferably, the visual image generating means is of the computer-generated image (C.G.I.) type and simultaneously computes corresponding left-eye and right-eye images, to provide corresponding modulation signals for the said left-eye and right-eye laser beam modulators.